Help identify a yellow headed bird

Observation - Help identify a yellow headed bird - UK and Ireland. Description: I live in a rural village surrounded by arable farmland in East Anglia. In my garden I have lots of bird feeders. Underneath the bird feeders (never on them) - I often see a yellow headed bird which I am struggling to identify. It is the size of a chaffi

I live in a rural village surrounded by arable farmland in East Anglia. In my garden I have lots of bird feeders. Underneath the bird feeders (never on them) - I often see a yellow headed bird which I am struggling to identify. It is the size of a chaffinch with long tail, a brown body (sparrow-like) and a yellow head with brown markings. It could be a yellow-hammer but the colouring doesnt seem quite right and I know they aren't normally seen in gardens. Any thoughts?